09 C6 A6 Vette, some kind of TQ limit hit at 680ftlbs, any idea's?

[9secVette]

I have tuned a bunch of high HP A6's, but I think they were all older models maybe. This 09 will have a perfect graph going on, and hit a brick wall at 680 rwtq. It will shut the fuel off (pressures etc all good) and the car goes 20:1. Same place every time, nearly exactly.

The car had been supercharged for some time, all I did this round was add a few pounds of boost with a pulley drop. The car was about 650 rwhp/tq before for about a year. The car is ran in SD/ MAF off, all the basic TQ tables have been raised, I have done straight percentage drops to both the IFR and VE table equally to see if that would register less TQ, but it didnt make any difference.

Any idea's? the trans tq tables have been maxed also.

thanks for any help

[Redline Motorsports]

It could be in either the E38 or T43 since they both talk to each other about "reported load". If you want to send the files I could look and see...or post them.... just to ask....what injectors and how far are they being pushed??

Also why did you alter the IFR and VE? Just for a "gross" test?

Howard

[9secVette]

It could be in either the E38 or T43 since they both talk to each other about "reported load". If you want to send the files I could look and see...or post them.... just to ask....what injectors and how far are they being pushed??

Also why did you alter the IFR and VE? Just for a "gross" test?

Howard


Thanks for responding Howard,
I did a quick even percentage drop of both the VE and IFR tables to see if that would make the pcm think it was producing less TQ. I would not leave it that way, I figured it was worth a shot as a test procedure. It actually surprised me how close the tune was from it being properly scaled.
I have built several high HP manual 09's now without issue, but this A6 shuts the car down fuel wise like it hit the rev limit. I beleive there might be a max tq table for the trans tune that is causing this to happen so consistently that might have started in the 09 files, but thats just my theory. The TQ tables in the trans tune are pretty cut and dry, and I maxed them all, but who knows, maybe I missed something.

[Redline Motorsports]

Personally I think we are still missing some "key" A6 tables to address items like this.......I think HP has a few tables that are more expanded in the torque management area......hate to say it..

[9secVette]

Im going to pull it in HP and take a look. If that doesnt do it I'll forward the tune over to you if you wouldnt mind?

[9secVette]

Just to give the answer to this, it's starts with me over looking the obvious... (as usual in these situations)

This car oddly just locked me out of the ECM a while back, never figured that one out, it ran fine but I couldnt make changes. Anyway, when I installed a new ECM I copy and pasted the file just incase the file was corrupt or something, and I forgot to raise the speed limiters. While on the dyno with ABS codes... it was shutting the car off.

Thanks for the help though, hopefully this helps someone else.

[joecar]

9SV,

Thanks for the follow up... so it was the speed limiters...?

[zbadestz]

9SV where are you out of? Is the above vette mentioned on a stock trans?

[68problemchild]

Speed limters are located on what parameter? Need to check this issue on my tune with a similar problem.

Thanks so much.